Tone synthesizing device and method based on physical model tone generator

Abstract

Physical model tone generator, which includes a loop section with a signal delay element, generates a driving signal by modifying a loop output signal from the loop in accordance with a performance parameter such as a bowing velocity, and introduces the generated driving signal to the loop. This way, the tone generator generates a tone signal with a characteristic controlled by the performance parameter, in a pitch period corresponding to a time delay of the loop. To generate the driving signal, a nonlinear conversion section performs a nonlinear conversion on an input signal based on the loop output signal and performance parameter. The conversion section switches an input-output characteristic, to be used for converting the input signal, into one of at least first and second input-output characteristics in accordance with intensity of a signal based on the loop output signal or the input signal, so that a desired nonlinear conversion characteristic is achieved. Control section restrains a period, in which the first input-output characteristic shifts to the second input-output characteristic, from becoming shorter than the pitch period of a tone based on the loop output signal. This arrangement can prevent the shift from the first input-output characteristic to the second input-output characteristic from taking place frequently within a single period of the tone pitch and thereby avoid a high-order vibration mode.